More than 1,000 complaints a year are called in, and the group carries out its own investigations.

Still, Western military and intelligence officials say they do know that three distinct groups are carrying out the attacks here.

Some local groups took part in attacks on private houses and carried out other violent activities.

The groups carry out in-depth research, report and present their findings.

The group carried out preliminary studies of the immediate area before starting the project.

Last year, a group of researchers carried out what may be the most extensive study on the subject to date.

A small, elite group of leaders already within the government structure carries out a coup.

The group have carried out many more attacks against the Guards in the province.

The group has carried out many attacks against Israel in recent years.

The group has been carrying out ever more brazen attacks.